Below is a walkthrough for the Clerical Error side quest in Tiny Tina’s Wonderlands. To obtain this quest, speak with Trystrom in the Overworlds.
Reach Temple of Faith
Follow the objective and enter the dungeon. You’ll have to complete 2 encounters to receive a chest containing the Scroll of Eternal Faith. Grab the scroll then head through the portal to exit the temple.
Return to Trystrom
Head back to Trystrom and speak with him to complete the quest.